PANTHER: AZD8931, inhibitor of EGFR, ERBB2 and ERBB3 signalling, combined with FOLFIRI: a Phase I/II study to determine the importance of schedule and activity in colorectal cancer

BACKGROUND

Epidermal growth factor receptor (EGFR) is a therapeutic target to which HER2/HER3 activation may contribute resistance. This Phase I/II study examined the toxicity and efficacy of high-dose pulsed AZD8931, an EGFR/HER2/HER3 inhibitor, combined with chemotherapy, in metastatic colorectal cancer (CRC).

METHODS

Treatment-naive patients received 4-day pulses of AZD8931 with irinotecan/5-FU (FOLFIRI) in a Phase I/II single-arm trial. Primary endpoint for Phase I was dose limiting toxicity (DLT); for Phase II best overall response. Samples were analysed for pharmacokinetics, EGFR dimers in circulating exosomes and Comet assay quantitating DNA damage.

RESULTS

Eighteen patients received FOLFIRI and AZD8931. At 160 mg bd, 1 patient experienced G3 DLT; 160 mg bd was used for cohort expansion. No grade 5 adverse events (AE) reported. Seven (39%) and 1 (6%) patients experienced grade 3 and grade 4 AEs, respectively. Of 12 patients receiving 160 mg bd, best overall response rate was 25%, median PFS and OS were 8.7 and 21.2 months, respectively. A reduction in circulating HER2/3 dimer in the two responding patients after 12 weeks treatment was observed.

CONCLUSIONS

The combination of pulsed high-dose AZD8931 with FOLFIRI has acceptable toxicity. Further studies of TKI sequencing may establish a role for pulsed use of such agents rather than continuous exposure.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov number: NCT01862003.

Harnessing cytokines and chemokines for cancer therapy

During the past 40 years, cytokines and cytokine receptors have been extensively investigated as either cancer targets or cancer treatments. A strong preclinical rationale supports therapeutic strategies to enhance the growth inhibitory and immunostimulatory effects of interferons and interleukins, including IL-2, IL-7, IL-12 and IL-15, or to inhibit the inflammatory and tumour-promoting actions of cytokines such as TNF, IL-1β and IL-6. This rationale is underscored by the discovery of altered and dysregulated cytokine expression in all human cancers. These findings prompted clinical trials of several cytokines or cytokine antagonists, revealing relevant biological activity but limited therapeutic efficacy. However, most trials involved patients with advanced-stage disease, which might not be the optimal setting for cytokine-based therapy. The advent of more effective immunotherapies and an increased understanding of the tumour microenvironment have presented new approaches to harnessing cytokine networks in the treatment of cancer, which include using cytokine-based therapies to enhance the activity or alleviate the immune-related toxicities of other treatments as well as to target early stage cancers. Many challenges remain, especially concerning delivery methods, context dependencies, and the pleiotropic, redundant and often conflicting actions of many cytokines. Herein, we discuss the lessons learnt from the initial trials of single-agent cytokine-based therapies and subsequent efforts to better exploit such agents for the treatment of solid tumours.

Phase I clinical trial repurposing all-trans retinoic acid as a stromal targeting agent for pancreatic cancer

Pre-clinical models have shown that targeting pancreatic stellate cells with all-trans-retinoic-acid (ATRA) reprograms pancreatic stroma to suppress pancreatic ductal adenocarcinoma (PDAC) growth. Here, in a phase Ib, dose escalation and expansion, trial for patients with advanced, unresectable PDAC (n = 27), ATRA is re-purposed as a stromal-targeting agent in combination with gemcitabine-nab-paclitaxel chemotherapy using a two-step adaptive continual re-assessment method trial design. The maximum tolerated dose (MTD) and recommended phase 2 dose (RP2D, primary outcome) is the FDA/EMEA approved dose of gemcitabine-nab-paclitaxel along-with ATRA (45 mg/m2 orally, days 1-15/cycle). Dose limiting toxicity (DLT) is grade 4 thrombocytopenia (n = 2). Secondary outcomes show no detriment to ATRA pharmacokinetics.. Median overall survival for RP2D treated evaluable population, is 11.7 months (95%CI 8.6-15.7 m, n = 15, locally advanced (2) and metastatic (13)). Exploratory pharmacodynamics studies including changes in diffusion-weighted (DW)-MRI measured apparent diffusion coefficient after one cycle, and, modulation of cycle-specific serum pentraxin 3 levels over various cycles indicate stromal modulation. Baseline stromal-specific retinoid transport protein (FABP5, CRABP2) expression may be predicitve of response. Re-purposing ATRA as a stromal-targeting agent with gemcitabine-nab-paclitaxel is safe and tolerable. This combination will be evaluated in a phase II randomized controlled trial for locally advanced PDAC. Clinical trial numbers: EudraCT: 2015-002662-23; NCT03307148. Trial acronym: STARPAC.

Neuroendocrine tumours of the gallbladder: three cases and a review of the literature

Primary neuroendocrine tumours (NETs) of the gallbladder are rare. In the absence of any randomised controlled trials or prospective case series, we sought trends for clinical presentation and management based on 60 patients from published literature over the last 15 years, as well as three patients from our experience, and categorised them into various subgroups according to the WHO classification for NETs. Well-differentiated NETs have an indolent course and better prognosis. Poorly differentiated neuroendocrine carcinomas, which may be of large-cell or small-cell type and may coexist with other types of carcinoma, have a poor outcome. A variety of surgical and chemotherapeutic approaches have been adopted. Surgical excision appears to prolong life, with chemotherapy perhaps adding a marginal advantage.

Pharmacokinetically guided phase I trial of topotecan and etoposide phosphate in recurrent ovarian cancer

A pharmacokinetically guided phase I study of topotecan and etoposide phosphate was conducted in recurrent ovarian cancer. The scheduling of the topoisomerase I and II inhibitors was determined using in vitro activity data. All patients had recurrent disease following prior platinum-containing chemotherapy. Patients had a World Health Organisation performance status of 0–2 and adequate bone marrow, renal and hepatic function. Treatment was with topotecan intravenously for 5 days followed immediately by a 5-day intravenous infusion of etoposide phosphate (EP), with pharmacokinetically guided dose adjustment. Plasma etoposide levels were measured on days 2 and 4 of the infusion. A total of 21 patients entered the study. In all, 48% were platinum resistant and 71% had received prior paclitaxel. The main toxicities were haematological, short lived and reversible. A total of 29% of patients experienced grade 4 thrombocytopenia and 66% grade 4 neutropenia after the first cycle. Neutropenia and thrombocytopenia was dose limiting. The maximum-tolerated dose was topotecan 0.85 mg m⁻² day⁻¹ days 1–5 followed immediately by a 5-day infusion of EP at a plasma concentration of 1 μg ml⁻¹. The response rate (RR) was 28% in 18 evaluable patients. There was marked interpatient variability in topoisomerase IIα levels measured from peripheral lymphocytes, with no observed increase following topotecan. This regimen of topotecan followed by EP demonstrated good activity in recurrent ovarian cancer and was noncrossresistant with paclitaxel. Both the toxicity and RR was higher than would be expected from the single agent data, in keeping with synergy of action.

The in vitro effects of CRE-decoy oligonucleotides in combination with conventional chemotherapy in colorectal cancer cell lines

The cAMP response element consensus sequence directs the transcription of a wide range of genes. A 24-mer single-stranded cAMP response element decoy oligonucleotide (CDO) has been shown to compete with these sequences for binding transcription factors and therefore interferes with cAMP-induced gene transcription. We have examined the effect of this CDO alone and in combination with a range of common chemotherapeutic agents in colorectal cancer cell lines. CDO had a potent anti-proliferative effect in colorectal cell lines, yet, a similar enhancement of cell death was not observed. Simple drug-drug interaction studies showed that combining CDO with chemotherapy resulted in an enhancement of the antiproliferative effects. Furthermore, this cytostatic effect was protracted and associated with an increase in senescence-associated beta-galactosidase activity at pH 6. There is a possible role for p21(waf1) in mediating this effect, as the enhancement of cell growth inhibition was not observed in cells lacking the ability to correctly upregulate this protein. Additionally, significant decreases in cyclin-dependent kinase (CDK) 1 and CDK 4 function were seen in the responsive cells. These data provide a possible model of drug interaction in colorectal cell lines, which involves the complex interplay of the molecules regulating the cell cycle. Clinically, the cytostatic ability of CDO could improve and enhance the antiproliferative effects of conventional cytotoxic agents.

s-Thalidomide has a greater effect on apoptosis than angiogenesis in a multiple myeloma cell line

s-Thalidomide has proven efficacy in multiple myeloma. Although it has both antiangiogenic and pro-apoptotic effects, its primary mode of therapeutic action remains unclear. We have investigated the changes to the expression of genes involved with these cellular processes following culture with s-thalidomide in the U266 MM cell line. Cells were cultured with s-thalidomide (0-1000 microM), and cell parameters, including apoptosis, were assessed on day 3. RNA was extracted from cells cultured for 24 h at the IC(50) concentration of s-thalidomide, and changes to gene expression were investigated by microarray methodologies. A reduction in cell viability was observed in U266 cells cultured with s-thalidomide (IC(50): 362 microM), which were mirrored by significant increases in apoptosis (for example, 200 microM on day 3: 40.3+/-3.1% vs. 3.2+/-0.4% on day 0; P<0.001). There were changes in the expression profile of genes involved in angiogenesis and apoptosis, but the changes were most dramatic in the apoptotic genes. In particular, the expression of I-kappaB kinase was decreased by two-fold, which was associated with a four-fold decrease in NF-kappaB expression. These data correlated with immunoblotting analyses, which showed significant increases in I-kappaB protein levels and decreased NF-kappaB activity. Additionally, the Bax : Bcl-2 ratio was significantly increased. Our data suggest that both angiogenic and apoptotic genes and proteins are affected by s-thalidomide. Additionally, a dramatic decrease in Bcl-2 expression with s-thalidomide suggests a possible enhancement of cytotoxic effect if combined with other cytotoxic agents.

Use of positron emission tomography in pharmacokinetic studies to investigate therapeutic advantage in a phase I study of 120-hour intravenous infusion XR5000

PURPOSE

XR5000 (N-[2-(dimethylamino)ethyl]acridine-4-carboxamide) is a topoisomerase I and II inhibitor. Because the cytotoxicity of XR5000 increases markedly with prolonged exposure, we performed a phase I study of weekly XR5000 by 120-hour continuous infusion over 3 weeks.

PATIENTS AND METHODS

Twenty-four patients with advanced solid cancer were treated at seven dose levels (700 to 4,060 mg/m2/120 hrs) for a total of 67 cycles. Three patients underwent positron emission tomography (PET) studies at the maximum-tolerated dose (MTD) to evaluate normal tissue and tumor carbon-11 radiolabeled XR5000 ([11C]XR5000) pharmacokinetics.

RESULTS

The dose-limiting toxicity was National Cancer Institute Common Toxicity Criteria (version 1) grade 4 chest and abdominal pain affecting the single patient receiving 4,060 mg/m2/120 hours, and the MTD was 3,010 mg/m2/120 hours. Other grade 3-4 toxicities, affecting single patients at the MTD, were myelosuppression (grade 4), raised bilirubin, vomiting, and somnolence (all grade 3). There was one partial response (adenocarcinoma of unknown primary); the remainder had progressive disease. [11C]XR5000 distributed well into the three tumors studied by PET. Tumor uptake (maximum concentration or area under the concentration versus time curve [AUC]) was less than in normal tissue in which the tumors were located. Tumor exposure (AUC; mean +/- SD in m2/mL/sec) increased when [(11)C]XR5000 was administered during an infusion of XR5000 (0.242 +/- 0.4), compared with [11C]XR5000 given alone (0.209 +/- 0.04; P <.05), indicating that tumor drug exposure was not saturated [corrected].

CONCLUSION

The recommended dose for XR5000 in phase II studies is 3,010 mg/m2/120 hours. PET studies with 11C-labeled drug were feasible and demonstrated in vivo distribution into tumors. Saturation of tumor exposure was not reached at the MTD.

Low-dose IFN-gamma induces tumor MHC expression in metastatic malignant melanoma

Specific antitumor immune responses require expression of MHC class I or II molecules on tumor cells, and MHC antigen down-regulation is a presumed tumor growth promoting mechanism. Because IFN-gamma up-regulates tumor MHC antigen expression in vitro, in this Phase II trial of an immunologically active dose and schedule we evaluated whether this was the case in vivo. Twenty-three patients with metastatic melanoma were treated with IFN-gamma 100 microg/m(2) s.c. once weekly for a maximum of 6 months. There were three complete responses, now maintained for 53, 36, and 25 months. The remainder had progressive disease. The treatment was well tolerated, with no toxicity exceeding National Cancer Institute Common Toxicity Criteria grade II. Immunohistochemical analysis of tumor biopsies during treatment was performed using monoclonal antibodies to HLA class I (W/632) and class II (CR3/43) monomorphic determinants. HLA class I was down-regulated in 2 of 19 patients pretreatment and up-regulated by IFN-gamma in both. HLA class II was down-regulated pretreatment in 14 of 18 patients and up-regulated by IFN-gamma in 6 (43%). The HLA up-regulation persisted throughout the study. IFN-gamma induced significant but short-lived up-regulation of surrogate markers of monocyte activation (serum neopterin) and class I up-regulation (serum beta-2-microglobulin) in most patients. There was no consistent relationship between surrogate marker up-regulation, tumor antigen up-regulation, and responses. The study shows that the significant immune modulation induced by IFN-gamma does not correlate with tumor responses and that the serum surrogate marker changes do not reflect tumor events. The durable and long-lived responses, clear demonstration of tumor MHC up-regulation, and low toxicity suggest that weekly IFN-gamma 100 microg/m(2) would be a useful addition to chemoimmunotherapeutic regimens.

Phase I and pharmacological study of the oral matrix metalloproteinase inhibitor, MMI270 (CGS27023A), in patients with advanced solid cancer

This Phase I study of MMI270, an p.o. administered matrix metalloproteinase inhibitor, assessed toxicity, pharmacokinetics, and tumor response data and investigated markers of biological activity to recommend a dose for Phase II studies. MMI270 was administered continuously at seven dose levels (50 mg once daily to 600 mg three times/day). Patients were evaluated for toxicity and tumor response, and blood and urine samples were taken for pharmacokinetics, bone resorption markers, direct targets of the inhibitor [matrix metalloproteinase-2 (MMP-2), MMP-8, and MMP-9], indirect targets [tissue inhibitor of metalloproteinase-1 (TIMP-1), TIMP-2, basic fibroblast growth factor, vascular endothelial growth factor, vascular cell adhesion molecule-1, soluble urokinase plasminogen activator receptor, and cathepsins B and H] and for a tumor necrosis factor-alpha cytokine release assay. Ninety-two patients were entered. There was no myelotoxicity. Eighteen patients developed a widespread maculopapular rash, which increased in frequency and severity at doses > or = 300 mg bid. Thirty nine patients developed musculoskeletal side effects, which were related to duration of treatment, not to dose level. Pharmacokinetics were linear, and MMI270 was rapidly absorbed and eliminated with minimal accumulation on chronic dosing. Sustained plasma concentrations in excess of 4 x mean IC(50) for the target enzymes were observed at dose levels > or = 150 mg bid. There were no tumor regressions; however, 19 patients had stable disease for > or = 90 days. There was a dose-response increase of MMP-2 and TIMP-1 with MMI270. Transient effects on the bone resorption markers were detected. MMI270 was generally well tolerated, with adequate plasma levels for target enzyme inhibition. The two main toxicities were rash, resulting in a maximum tolerated dose of 300 mg bid and musculoskeletal side effects. Biological marker data indicate drug effects. The rise in TIMP-1 suggests that a reflex rise in inhibitors could modify the effects of MMI270. The recommended Phase II dose is 300 mg bid.

Phase I and pharmacokinetic study of PKC412, an inhibitor of protein kinase C

PURPOSE

N-Benzoyl staurosporine (PKC412) is a protein kinase C inhibitor with antitumor activity in laboratory models. We determined the toxicity of oral PKC412 administered daily for repeat cycles of 28 days.

PATIENTS AND METHODS

Thirty-two patients with advanced solid cancers were treated at seven dose levels (12.5 to 300 mg daily) for a total of 68 cycles.

RESULTS

The most frequent treatment-related toxicities were nausea, vomiting, fatigue, and diarrhea. At the two top dose levels (225 and 300 mg/d), 15 of 16 patients experienced nausea/vomiting (common toxicity criteria [CTC], version 1), grade 2 in nine of 16 and grade 3 in three of 16 patients; and six of 16 patients developed CTC grade 2 diarrhea. After 1 month of treatment, there were significant reductions in circulating lymphocyte (P <.02) and monocyte (P <.01) counts in patients receiving doses > or = 100 mg/d. Nevertheless, only two patients developed myelosuppression (both grade 2). Of two patients with progressive cholangiocarcinoma, one attained stable disease lasting 4.5 months and one a partial response lasting 4 months. There was a linear relationship between PKC412 dose and area under the curve (0-24 hours) and maximum plasma concentration with marked interpatient variability. The estimated median elimination half-life was 1.6 days (range, 0.9 to 4.0 days), and a metabolite with a median half-life of 36 days was detected. Steady-state PKC412 plasma levels at the top three dose cohorts (150 to 300 mg) were five to 10 times the cellular 50% inhibitory concentration for PKC412 of 0.2 to 0.7 micromol/L.

CONCLUSION

PKC412 can be safely administered by chronic oral therapy, and 150 mg/d is suitable for phase II studies. The pharmacokinetics and lack of conventional toxicity indicate that pharmacodynamic measures may be additionally needed to optimize the drug dose and schedule.

A phase II study of razoxane, an antiangiogenic topoisomerase II inhibitor, in renal cell cancer with assessment of potential surrogate markers of angiogenesis

Renal cell carcinoma (RCC) is an angiogenic tumor resistant to standard cytotoxic chemotherapeutic agents. Although often responsive to immunomodulatory agents including interleukin 2 and IFN-alpha, the overall results in randomized Phase III studies are disappointing with only modest improvements in overall survival. This Phase II study evaluated the efficacy and tolerability of razoxane, an antiangiogenic topoisomerase II inhibitor, in 40 patients (32 men, 8 women; age: range, 31-76 years; median, 58 years) with inoperable RCC. Twenty patients received razoxane 125 mg p.o., twice a day for 5 days each week for 8 weeks (one cycle). This was repeated in patients with stable disease (StD), but was discontinued after 16 weeks if there was no evidence of an objective response. Because minimal toxicity was seen, subsequent patients (n = 20) were treated until progressive disease (PD) was documented. Of 38 evaluable patients, 11 (29%) had StD for a minimum of 4 months, and the remainder had PD. Median overall survival was 7.3 months. Duration of survival was significantly better in patients with StD compared with those with PD (P = 0.003). The effect of treatment on six potential surrogate serum/plasma (vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), urokinase plasminogen activator soluble receptor (uPAsr), E-selectin, vascular cell adhesion molecule-1 (VCAM-1) and von Willebrand's factor (vWF) and two urinary (VEGF and bFGF) markers of angiogenesis was evaluated before and after 1 cycle of treatment. Pretreatment serum VEGF and E-selectin levels above the median value were associated with a poor prognosis. Serum VCAM-1 levels and urinary VEGF levels rose significantly after one cycle in patients with PD but not in those with StD. Serum VEGF, bFGF, VCAM-1 and vWF, plasma uPAsr and urinary bFGF levels were significantly higher in PD patients compared with StD patients before and/or after 1 cycle of treatment. In conclusion, razoxane is an antiangiogenic agent that has minimal toxicity and that requires further evaluation in combination with other active agents in the treatment of RCC. Surrogate serum and urinary markers of angiogenesis may have a role to play in predicting disease response and overall survival in RCC.

Induction of thymidine phosphorylase as a pharmacodynamic end-point in patients with advanced carcinoma treated with 5-fluorouracil, folinic acid and interferon alpha

Thymidine phosphorylase (TP) is an essential enzyme for the biochemical activation of 5-fluorouracil (5-FU). Interferon upregulates TP in vivo, although the dose and schedule of interferon for optimal biomodulation of 5-FU is not known. In this study, TP activity was measured in peripheral blood lymphocytes (PBLs) from patients with advanced carcinoma receiving treatment with 5-FU and folinic acid. Cohorts of patients were treated with interferon alpha (IFNalpha), immediately prior to 5-FU/folinic acid, at doses of 3 MIU m(-2), 9 MIU m(-2) and 18 MIUm(-2). IFNalpha was administered on day 0 cycle two, day-1 and day 0 cycle three and day-2, day-1 and day 0 cycle four. A fourth cohort was treated with IFNalpha 9 MIU m(-2) three times per week from cycle 2 onwards. Twenty-one patients were entered into the study with 19 evaluable for response. Six patients (32%) had stable disease and 13 (68%) progressive disease. There were no grade-IV toxicities. TP activity was detected in PBLs from all patients with wide interpatient variability in constitutive TP activity prior to chemotherapy, and in response to IFNalpha. 5-FU/folinic acid alone did not induce TP activity but a single dose of IFNalpha led to upregulation of TP within 2 h of administration with a further increase by 24 h (signed rank test, P = 0.006). TP activity remained elevated for at least 13 days (signed rank test, P= 0.02). There were no significant differences in TP activity between schedules or with additional doses of IFNalpha. A single dose of IFNalpha as low as 3 MIU m(-2) can cause sustained elevation of PBL TP activity in vivo indicating that biochemical markers are important pharmacodynamic endpoints for developing optimal schedules of IFNalpha for biomodulation of 5-FU.

Phase II study of the oxygen saturation curve left shifting agent BW12C in combination with the hypoxia activated drug mitomycin C in advanced colorectal cancer

BW12C (5-[2-formyl-3-hydroxypenoxyl] pentanoic acid) stabilizes oxyhaemoglobin, causing a reversible left-shift of the oxygen saturation curve (OSC) and tissue hypoxia. The activity of mitomycin C (MMC) is enhanced by hypoxia. In this phase II study, 17 patients with metastatic colorectal cancer resistant to 5-fluorouracil (5-FU) received BW12C and MMC. BW12C was given as a bolus loading dose of 45 mg kg(-1) over 1 h, followed by a maintenance infusion of 4 mg kg(-1) h(-1) for 5 h. MMC 6 mg m(-2) was administered over 15 min immediately after the BW12C bolus. The 15 evaluable patients had progressive disease after a median of 2 (range 1-4) cycles of chemotherapy. Haemoglobin electrophoresis 3 and 5 h after the BW12C bolus dose showed a fast moving band consistent with the BW12C-oxyhaemoglobin complex, accounting for approximately 50% of total haemoglobin. The predominant toxicities--nausea/vomiting and vein pain--were mild and did not exceed CTC grade 2. Liver 31P magnetic resonance spectroscopy of patients with hepatic metastases showed no changes consistent with tissue hypoxia. The principle of combining a hypoxically activated drug with an agent that increases tissue hypoxia is clinically feasible, producing an effect equivalent to reducing tumour oxygen delivery by at least 50%. However, BW12C in combination with MMC for 5-FU-resistant colorectal cancer is not an effective regimen. This could be related to drug resistance rather than a failure to enhance cytotoxicity.

Phase II study of second-line therapy with DTIC, BCNU, cisplatin and tamoxifen (Dartmouth regimen) chemotherapy in patients with malignant melanoma previously treated with dacarbazine

This study assessed response rates to combination dacarbazine (DTIC), BCNU (carmustine), cisplatin and tamoxifen (DBPT) chemotherapy in patients with progressive metastatic melanoma previously treated with DTIC, as an evaluation of DBPT as a second-line regimen, and as an indirect comparison of DBPT with DTIC. Thirty-five consecutive patients received DBPT. The patients were divided into two groups. Group 1 comprised 17 patients with progressive disease (PD) on DTIC + tamoxifen therapy who were switched directly to DBPT. Group 2 comprised 18 patients not immediately switched to DBPT and included patients who had either a partial response (PR; one patient) or developed stable disease (SD; four patients) with DTIC, or received adjuvant DTIC (nine patients). All except four patients had received tamoxifen at the time of initial DTIC treatment. Median times since stopping DTIC were 22 days (range 20-41) and 285 days (range 50-1,240) in Groups 1 and 2 respectively. In Group 1, one patient developed SD for 5 months and the remainder had PD. In Group 2, there were two PRs, four patients with SD (4, 5, 6, and 6 months), and 11 with PD. These results indicate that the DBPT regimen is not of value in melanoma primarily refractory to DTIC. There were responses in patients not directly switched from DTIC to DBPT, suggesting combination therapy may be of value in a small subgroup of melanoma patients.

Evaluation of the alkaline comet assay and urinary 3-methyladenine excretion for monitoring DNA damage in melanoma patients treated with dacarbazine and tamoxifen

PURPOSE

To develop, using dacarbazine as a model, reliable techniques for measuring DNA damage and repair as pharmacodynamic endpoints for patients receiving chemotherapy.

METHODS

A group of 39 patients with malignant melanoma were treated with dacarbazine 1 g/m(2) i.v. every 21 days. Tamoxifen 20 mg daily was commenced 24 h after the first infusion and continued until 3 weeks after the last cycle of chemotherapy. DNA strand breaks formed during dacarbazine-induced DNA damage and repair were measured in individual cells by the alkaline comet assay. DNA methyl adducts were quantified by measuring urinary 3-methyladenine (3-MeA) excretion using immunoaffinity ELISA. Venous blood was taken on cycles 1 and 2 for separation of peripheral blood lymphocytes (PBLs) for measurement of DNA strand breaks.

RESULTS

Wide interpatient variation in PBL DNA strand breaks occurred following chemotherapy, with a peak at 4 h (median 26.6 h, interquartile range 14.75-40.5 h) and incomplete repair by 24 h. Similarly, there was a range of 3-MeA excretion with peak levels 4-10 h after chemotherapy (median 33 nmol/h, interquartile range 20.4-48.65 nmol/h). Peak 3-MeA excretion was positively correlated with DNA strand breaks at 4 h (Spearman's correlation coefficient, r=0.39, P=0.036) and 24 h (r=0.46, P=0.01). Drug-induced emesis correlated with PBL DNA strand breaks (Mann Whitney U-test, P=0.03) but not with peak 3-MeA excretion.

CONCLUSIONS

DNA damage and repair following cytotoxic chemotherapy can be measured in vivo by the alkaline comet assay and by urinary 3-MeA excretion in patients receiving chemotherapy.

Phase I trial of the selective mitochondrial toxin MKT077 in chemo-resistant solid tumours

BACKGROUND

MKT077 is a rhodacyanine dye analogue which preferentially accumulates in tumour cell mitochondria. It is cytotoxic to a range of tumours. In this phase I study, MKT077 was administered as a five-day infusion once every three weeks.

PATIENTS AND METHODS

Ten patients, median age 59 (38-70) years, with advanced solid cancers were treated at three dose levels: 30, 40 and 50 mg/m2/day for a total of 18 cycles. 31Phosphorus magnetic resonance spectroscopy (MRS) was used to evaluate the effect of MKT077 on skeletal muscle mitochondrial function.

RESULTS

The predominant toxicity was recurrent reversible functional renal impairment (grade 2, two patients). One patient with renal cancer attained stable disease and the remainder progressive disease. There were no MRS changes in the first or second treatment cycles but one patient received 11 treatment cycles and developed changes consistent with a mitochondrial myopathy. Mean values for all pharmacokinetic parameters were at sub micromolar levels and did not exceed IC50 values (> or = 1 microM).

CONCLUSIONS

Because of the renal toxicity, and animal studies showing MKT077 causes eventual irreversible renal toxicity, further recruitment was halted. The study shows, however, that it is feasible to target mitochondria with rhodacyanine analogues, if drugs with higher therapeutic indices could be developed.

A phase II study of the modulation of 5-fluorouracil and folinic acid with high-dose infusional hydroxyurea in metastatic colorectal carcinoma

BACKGROUND

Hydroxyurea (HU), an inhibitor of ribonucleotide reductase, may potentiate the activity of 5-fluorouracil (5-FU) and folinic acid (FA) by reducing the deoxyribonucleotide pool available for DNA synthesis and repair. However as HU may inhibit the formation of 5-fluoro-2-deoxyuridine-5-monophosphate (FdUMP), one of the principal active metabolites of 5-FU, the scheduling of HU may be critical. In vitro experiments suggest that administration of HU following 5-FU, maintaining the concentration in the region of 1 mM for six or more hours, significantly enhances the efficacy of 5-FU.

PATIENTS AND METHODS

5-FU/FA was given as follows: days 1 and 2-FA 250 mg/m2 (max. 350 mg) over two hours followed by 5-FU 400 mg/m2 by intravenous bolus (i.v.b.) over 15 minutes and subsequently 5-FU 400 mg/m2 infusion (ivi) over 22 hours. HU was administered on day 3 immediately after the 5-FU with 3 g i.v.b. over 15 minutes followed by 12 g ivi over 12 hours.

RESULTS

Thirty patients were entered into the study. Median survival was nine months (range 1-51+ months). There were eight partial responses (28%, 95% CI: 13%-47%). The median duration of response was 6.5 (range 4-9 months). Grade 3-4 toxicities included neutropenia (grade 3 in eight patients and grade 4 in five), anaemia (grade 3 in one patient) and diarrhoea (grade 3 in two patients). Neutropenia was associated with pyrexia in two patients. Phlebitis at the infusion site occurred in five patients. The treatment was complicated by pulmonary embolism in one patient and deep venous thrombosis in another.

CONCLUSION

HU administered in this schedule is well tolerated. Based on these results and those of other phase II studies, a randomised phase III study of 5-FU, FA and HU versus 5-FU and FA using the standard de Gramont schedule is recommended.

Phase I study of the novel cyclic AMP (cAMP) analogue 8-chloro-cAMP in patients with cancer: toxicity, hormonal, and immunological effects

The cyclic AMP (cAMP)-dependent protein kinase regulatory subunit RI is overexpressed in cancer cells. 8-Chloro-cAMP (8-Cl-cAMP) is an RII site-specific analogue that down-regulates RI and inhibits the growth of a wide range of cancer cells in vitro and in vivo. We performed a Phase I trial of 8-Cl-cAMP in 32 patients with malignancies that were refractory to standard treatments. 8-Cl-cAMP was initially given in a 1-month cycle by constant infusion at 0.005 mg/kg/h for 21 days, followed by 1 week of rest. The dose was escalated to 0.045 mg/kg/h, but hypercalcemia became the dose-limiting toxicity. The length of drug administration was, therefore, reduced to 5 days per week for the first 3 weeks of the cycle, but it was not possible to increase the drug dose without producing hypercalcemia. Hence, the length of drug administration was reduced to 3 days per week for the first 3 weeks of the cycle. The maximum tolerated dose for this regimen was 0.15 mg/kg/h, and the dose-limiting toxicities were reversible hypercalcemia and hepatotoxicity. Stable disease for > or =4 months was observed in two patients treated at > or =0.045 mg/kg. cAMP-dependent protein kinase is involved in hormone- and cytokine-mediated signaling, and so representative hormone, cytokine, and peripheral lymphocyte subsets were measured. The drug had a parathyroid hormone-like effect on calcium homeostasis and significantly increased circulating luteinizing hormone and 17-hydoxyprogesterone levels (P < 0.02 and P < 0.0006, respectively). We conclude that 8-Cl-cAMP is well tolerated without attendant myelotoxicity, and in this study, it was associated with biological effects. In Phase II studies, a dose of 0.11 mg/kg/h for 3 days per week would be appropriate.

Phase II study of RC-160 (vapreotide), an octapeptide analogue of somatostatin, in the treatment of metastatic breast cancer

RC-160 (octastatin/vapreotide) is a potent octapeptide analogue of somatostatin with growth inhibitory activity in experimental tumours in vitro and in vivo, including breast cancer. We evaluated the efficacy and tolerability of high-dose RC-160, 3 mg day(-1) on week 1 increased to 4.5 mg day(-1) for weeks 2-4 and subsequently 6 mg day(-1) until the end of treatment, administered by continuous subcutaneous infusion in the management of 14 women with previously treated metastatic breast cancer. The age range was 37-80 years (median 58.5 years) and performance status 0-2. The treatment was well tolerated with no dose reductions being required. No grade 3 or 4 toxicities were seen. Abscess formation developed at the infusion site in eight patients and erythema and discomfort was seen in a further three patients. A significant reduction in IGF-I levels occurred by day 7 and was maintained throughout the treatment. The lowest dose of RC-160 produced the maximal IGF-I response. Although there was no reduction in prolactin levels in patients whose baseline levels were normal, elevated prolactin levels found in three patients fell to within the normal range 7 days after commencing RC-160 treatment. A small but significant rise in fasting blood glucose levels was also recorded, the highest level on treatment being 7.6 mmol l(-1). No objective tumour responses were observed, all patients showing disease progression within 3 months of commencing treatment. These findings demonstrate that high-dose RC-160, administered as a continuous subcutaneous infusion, can reduce serum levels of the breast growth factors IGF-I and prolactin but is ineffective in the management of metastatic breast cancer. Encouraging preclinical anti-tumour activity and the favourable toxicity profile in patients suggest the merit of future studies combining RC-160 with anti-oestrogen, cytotoxic and anti-angiogenic agents.

A phase II study of bryostatin 1 in metastatic malignant melanoma

Bryostatin 1 is a protein kinase C partial agonist which has both antineoplastic and immune-stimulatory properties, including the induction of cytokine release and expansion of tumour-specific lymphocyte populations. In phase I studies, tumour responses have been observed in patients with malignant melanoma, lymphoma and ovarian carcinoma. The dose-limiting toxicity is myalgia. Sixteen patients (age 35-76 years, median 57 years) with malignant melanoma were treated. All had received prior chemotherapy. In each cycle of treatment, patients received bryostatin 25 degrees g m(-2) weekly for three courses followed by a rest week. The drug was given in PET diluent (10 microg bryostatin ml(-1) of 60% polyethylene glycol, 30% ethanol, 10% Tween 80) and infused in normal saline over 1 h. The principal toxicities were myalgia (grade 2, eight patients and grade 3, six patients) and grade 2 phlebitis (four patients), fatigue (three patients) and vomiting (one patient). Of 15 patients evaluable for tumour response, 14 developed progressive disease. One patient developed stable disease for 9 months after bryostatin treatment. In conclusion, single-agent bryostatin appears ineffective in the treatment of metastatic melanoma in patients previously treated with chemotherapy. It should, however, be investigated further in previously untreated patients.

A phase II study of mitomycin C and oral etoposide for advanced adenocarcinoma of the upper gastrointestinal tract

BACKGROUND

Mitomycin C and etoposide have both demonstrated activity against gastric carcinoma. Etoposide is a topoisomerase II inhibitor with evidence for phase-specific and schedule-dependent activity.

PATIENTS AND METHOD

Twenty-eight consecutive patients with advanced upper gastrointestinal adenocarcinoma were treated with intravenous (i.v.) bolus mitomycin C 6 mg/m2 on day 1 every 21 days to a maximum of four courses. Oral etoposide capsules 50 mg b.i.d. (or 35 mg b.i.d. liquid) were administered days 1 to 10 extending to 14 days in subsequent courses if absolute neutrophil count > 1.5 x 10(9)/l on day 14 of first course, for up to six courses.

RESULTS

Twenty-six patients were assessed for response of whom 12 had measurable disease and 14 evaluable disease. Four patients had a documented response (one complete remission, three partial remissions) with an objective response rate of 15% (95% confidence interval (95% CI) 4%-35%). Eight patients had stable disease and 14 progressive disease. The median survival was six months. The schedule was well tolerated with no treatment-related deaths. Nine patients experienced leucopenia (seven grade II and two grade III). Nausea and vomiting (eight grade II, one grade III), fatigue (eight grade II, two grade III) and anaemia (seven grade II, two grade III) were the predominant toxicities.

CONCLUSION

This out-patient schedule is well tolerated and shows modest activity in the treatment of advanced upper gastrointestinal adenocarcinoma. Further studies using protracted schedules of etoposide both orally and as infusional treatment should be developed.

Comparative effects of rapamycin, FK 506 and cyclosporine on antibody production, lymphocyte populations and immunoglobulin isotype switching in the rat

The immunosuppressive activity and comparative efficacy of rapamycin (RAPA), FK 506 and cyclosporine A (CsA) were investigated in rats following immunization with either xenogeneic sheep red blood cells (SRBC) or allogeneic blood transfusion. RAPA formulated in a polyethylene glycol vehicle, and at a dose of 1.5 mg.kg-1 i.p., was relatively ineffective when compared with FK 506 (1 mg.kg-1) or CsA (15 mg.kg-1) in suppressing antibody production to SRBC. Like FK 506 and CsA however, RAPA proved highly effective in suppressing both the B lymphocytosis and the increase in circulating major histocompatibility complex class II+ cells observed following immunization. All three immunosuppressants caused thymic medullary atrophy, with evidence of epithelial cell damage and increased macrophage phagocytic activity. Administered i.m. (3 mg.kg-1 in olive oil), RAPA was also highly effective in suppressing 1 degree alloantibody responses to MHC class I antigens following blood transfusion. Unlike FK 506 and CsA however, a short (14-day) course of RAPA following 1 degree immunization (transfusion) did no suppress 2 degree alloantibody responses elicited 6 weeks later. Moreover, RAPA did not prevent immunoglobulin isotype switching as observed with FK 506 and CsA. This may reflect the distinct mechanisms of action of RAPA and the latter two agents on T-cell activation/proliferation. Further comparative and combination studies of RAPA with in particular, CsA, are required to further explore to potential of RAPA as an immunotherapeutic agent.

The effects of rapamycin on humoral immunity in vivo. Suppression of primary responses but not of ongoing alloantibody synthesis or memory responses

The effect of rapamycin on primary and secondary alloantibody responses to major histocompatibility complex class I antigens was investigated in inbred rat strains. Primary anti-MHC class I alloantibody responses, detected by indirect hemagglutination and complement-dependent cytotoxicity assays, were abrogated in high-responder WAG (RT1u) recipients of DA (RT1a) blood transfusions, given on days 0 and 7 of a 14-day course of rapamycin (3 mg/kg/day). Antibody class studies showed that both IgM and IgG responses were equally effectively inhibited. Moreover, when these animals were rechallenged with DA transfusions, 28 days after drug withdrawal, they exhibited donor-specific humoral unresponsiveness. Similar results were observed in cyclosporine-treated rats. In preimmunized high-responder LEW (RT1(1)) rats with high titer anti-DA class I alloantibodies, a 35-day course of rapamycin (3 mg/kg/day) had no significant suppressive effect on serum alloantibody levels when compared with untreated preimmunized control animals. WAG rats were immunized by DA transfusions and serum antibody levels then allowed to decay over 16 weeks. The animals were then challenged with a further DA transfusion given on the second day of a 14-day course of rapamycin (3 mg/kg/day). Alloantibody responses to the challenge transfusion in this group were not, however, significantly suppressed when compared with a non-drug-treated control group. The results of this study indicate that rapamycin is a potent inhibitor of primary alloantibody synthesis in high-responder rat strains, but does not significantly suppress alloantibody synthesis in animals with established humoral reactivity. These results may be of relevance if rapamycin is to be used in clinical renal transplantation, because in man similar antibodies mediate hyperacute rejection, and when they develop after transplantation are associated with very high rates of rejection.

Breast vasculitis in association with breast gigantism in a pregnant patient with systemic lupus erythematosus

A 24 year old woman with systemic lupus erythematosus (SLE) developed widespread necrotic skin ulceration and gigantism of both breasts during an exacerbation of SLE in the last trimester of her second pregnancy. Over the remainder of the pregnancy the ulceration was only controlled by high dose corticosteroids. After parturition, however, it was possible to reduce the steroid dose without recurrence of the ulceration.

Immune responses to noninherited maternal RT1A antigens in inbred rats

Humoral responses to non-inherited maternal class I antigens (class I NIMAs) were assessed in 3 groups of inbred rats expressing the RT1u phenotype. Group 1 consisted of the progeny of (AO X DA)F1 X PVG matings; their haplotype was RT1u/c and their non-inherited maternal haplotype RT1a. Group 2 were the progeny of (AO X LEW)F1 X PVG matings the haplotype of which was also RT1u/c, but their non-inherited maternal haplotype was RT1l. Group 3 comprised 8 (AO X PVG)F1 (RT1u/c) hybrids. All rats received 2 intravenous blood transfusions (0.5 ml) from male DA (RT1Aa) donors on days 0 and 7. They were bled at weekly intervals for 6 weeks and again at 20 weeks after the first transfusion. Alloantibody responses to RT1Aa were assessed by an indirect hemagglutination assay (IHA)* and by a 51Chromium-release complement-dependent red cell cytotoxicity assay. All groups exhibited vigorous anti-class I antibody responses to the DA transfusions. No significant differences were detected, however, in antibody titers between the groups either by IHA or CDC or in the rates of decay of antibody titers up to week 20. In addition no blocking activity was found in sera obtained on day 0 from group 1 animals and tested for antiidiotypic antibody activity to cytotoxic anti-RT1Aa antibodies. In order to assess whether suppressor activity had been activated by the initial transfusions, in the animals in which class I NIMA was RT1Aa, all groups were rechallenged with a DA transfusion at week 20. All animals exhibited vigorous anamnestic responses to this challenge and no significant differences were detected between groups. In order to determine whether cellular tolerance to the noninherited maternal haplotype was present in group 1 animals, proliferative responses were assessed by one-way mixed lymphocyte cultures, using DA lymph node stimulator cells. No significant differences were detected in proliferative or kinetic responses between lymph node cells from rats the noninherited maternal haplotype of which was RT1a or from naive (AO X PVG)F1 hybrids. Peak proliferative responses to DA cells in rats the noninherited maternal haplotype of which was RT1l were similar, but maximal on day 4 as opposed to day 3. Hence in these inbred rat strains no evidence of humoral tolerance to class I NIMAs was detected. In addition there was no evidence of cellular tolerance to the noninherited maternal MHC haplotype.

Immunological aspects of clinical renal transplantation

Improved facilities for treating patients with end-stage renal failure have resulted in more elderly and debilitated patients being accepted for treatment. Renal transplantation is now the optimum form of treatment but organ procurement has failed to match clinical demand. Future developments may focus on further non-specific immunosuppressive agents. As one year survival rates for first cadaver allografts now exceed 85% in many units, the significance of new developments will be increasingly difficult to evaluate.

Reduction of sensitization induced by blood transfusion in the rat by monoclonal antibodies

Primary and secondary alloantibody responses were monitored in (AOxPVG)F1 hybrid rats after three transfusions of DA blood; the initial transfusion was either untreated or pretreated with monoclonal antibody directed to class I antigens or other cell surface markers. Mean antibody activity in recipient sera against class I DA antigens was significantly decreased by pretreatment with the monoclonal antibodies. The most marked suppression was associated with pretreatment by antibodies to the four major nonoverlapping epitopes of the RT1Aa antigen. Subsequent transfusions of DA blood failed to stimulate a secondary response. Crossreactivity of the alloantibody reactivity with BDIX antigens was diminished by pretreating the transfusions with rat anti-RT1A antibodies and, to a lesser extent, with a mouse monoclonal antibody (OX-18) to a common class I determinant. Monoclonal antibody pretreatment had no effect on the humoral response to class II DA antigens. These studies indicate that blood transfusions pretreated with monoclonal antibodies induce a less-potent cytotoxic humoral immune response and that reactivity is most effectively suppressed by completely masking the class I antigen. This technique may prove of clinical value in preventing the sensitization caused by blood transfusions in potential transplant recipients.

Lymphocytotoxins in sera from highly sensitized multiparous dialysis patients: antibody class, relationship with the HLA and with paternal antigens

1. Sera from 11 highly sensitized multiparous dialysis patients were studied in order to define the target antigens, antibody class and relationship with paternal HLA class I antigens of the underlying lymphocytotoxic antibodies. All sera contained lymphocytotoxic antibodies to over 70% of a panel of lymphocytes from 24 donors (panel reactivity greater than 70%). 2. Inhibition of cytotoxic activity against paternal lymphocytes by monoclonal antibodies to HLA framework determinants indicated that all 11 sera contained lymphocytotoxic antibodies to paternal class I antigens. In addition, five sera contained lymphocytotoxic antibodies to paternal class II antigens. 3. In order to determine the extent to which lymphocytotoxic antibodies were directed to paternal antigens, the panel reactivity of sera was compared before and after absorption with paternal peripheral blood lymphocytes. Over 50% of panel reactivity was absorbed from eight out of 11 sera, and in three of these 11 over 80% was absorbed. In the majority of patients this change in panel reactivity could be ascribed to binding of lymphocytotoxic antibodies to specific paternal class I antigens. 4. Digestion of sera with dithiothreitol had no significant effect on panel reactivity, indicating that the lymphocytotoxic antibodies were of immunoglobulin G class. 5. No sera reacted with either autologous lymphocytes or K562 cells, indicating an absence of autoantibodies. 6. These studies imply that panel-reactive lymphocytotoxic antibodies in the sera of highly sensitized multiparous patients are those which mediate hyperacute renal allograft rejection. Their development may be related to secondary humoral responses to antigens in blood transfusions from donors who share paternal class I specificities.

The effect of cyclosporin administered during a third-party blood transfusion protocol on humoral immune responses

Antigen pre-treatment in animals undoubtedly prolongs graft survival. In man, however, routine pre-transplantation blood transfusions have recently become controversial, principally because of the adverse effect of transfusion-induced sensitisation on graft survival rates. We have monitored the effect of cyclosporin administered during a planned programme of third-party blood transfusions on the development of both cytotoxic and anti-idiotypic antibodies. A total of 24 patients were recruited to the study; ten received cyclosporin with blood transfusions (BT) (group 1), 14 received BT alone (group 2). Anti-HLA antibodies developed in 3 of 9 patients in group 1 and 8 of 12 patients in group 2 (P less than 0.05). Anti-idiotypic antibody activity was detectable in 9 of 9 patients in group 1 and 7 of 12 patients in group 2 (P less than 0.006). The mechanism by which cyclosporin can prevent an anti-HLA antibody response and promote an anti-idiotypic response is unclear.

Cyclosporin A and the humoral response to blood transfusion in the rat: definition of antigens which suppress alloantibody formation

1. Blood transfusions improve renal allograft survival rates, but may induce antibodies which are directed to class I major histocompatibility complex antigens and mediate hyperacute transplant rejection. A model to study the development of such antibodies was developed in inbred strains of rats. 2. The influence of transplantation antigens shared between an initial course of blood transfusions, given with cyclosporin A, and a subsequent antigenic challenge (blood transfusion), given without cyclosporin A, on alloantibody responses to class I major histocompatibility complex antigens was then investigated. 3. Cyclosporin A administration prevented the development of alloantibodies to class I major histocompatibility complex antigens during the initial transfusion period. 4. After the challenge transfusions, alloantibody responses to class I major histocompatibility complex antigens were suppressed when class I major histocompatibility complex or minor histocompatibility antigens were shared between the initial and final transfusions. 5. This suppression only extended to third party class I antigens when minor histocompatibility complex antigens were shared between the initial and final transfusions. Sharing of class I or class II antigens had no effect on alloantibody responses to third party class I antigens coexpressed on the same cell. 6. These studies suggest that cyclosporin A given with blood transfusions may prevent clinical sensitization while permitting the development of suppressor activity, mediated by shared minor histocompatibility complex determinants, to a broad range of potential donor antigens.

Antigen presentation and HLA-DR expression by FK-506-treated human monocytes

The novel macrolide immunosuppressant FK-506 demonstrated superior potency to cyclosporin A (CsA) in the inhibition of purified protein derivative (PPD)-induced human T-cell proliferation. Pulsing of monocytes with PPD for 24 hr in the presence of FK-506 did not impair their capacity to subsequently induced the proliferation of purified autologous T cells. In contrast, FK-506 profoundly inhibited the proliferative response of T cells to antigen-pulsed monocytes. Recombinant IL-2, but not IL-1, partially restored the proliferative response to PPD in the presence of the drug. FK-506 had no effect on basal or rIFN-gamma-induced expression of HLA-DR on monocytic cell line cells. These findings provide the first evidence that FK-506 can profoundly inhibit soluble antigen-induced human T-cell proliferation at concentrations which do not significantly impair the accessory function of mononuclear phagocytes.

Influence of FK506 and cyclosporin A on alloantibody production and lymphocyte activation following blood transfusion

The effect of administration of cyclosporin A (CyA) or the novel macrolide FK506 was investigated in AO rats given DA blood transfusions. CyA (10 mg/kg, orally) or FK506 (1 mg/kg, intramuscularly) administered for 14 days from the time of transfusion effectively inhibited primary anti-MHC class I alloantibody production. This profound inhibitory effect persisted throughout the 2-month investigation period, with little increase in 'secondary' alloantibody production following a challenge injection 28 days after drug withdrawal. Flow cytometric analysis revealed no significant differences in the absolute numbers of W3/25+ (CD4+), OX-8+ (CD8+) or OX-12+ (B lymphocytes), in either the spleen or peripheral blood of transfused compared with normal, untreated animals. However, a small but significant increase in the numbers of splenocytes expressing the activation marker OX-40 (activated CD4+ cells) was observed in transfused animals. Either CyA or FK506 significantly reduced the number of cells expressing OX-39 (interleukin-2 receptors) and OX-40. Treatment of transfused animals with CyA, but not FK506 for 14 days resulted in minor, transient reduction in peripheral blood OX-19+ and W3/25+ cells, while 'sparing' the OX-8+ cells; these changes were not observed in spleens. In contrast, the absolute spleen cell numbers of OX-19+, W3/25+ and OX-8+ cells were significantly reduced in transfused animals given 14 days of FK506 treatment, while the corresponding blood cells were unaffected. Induction of splenic lymphoproliferative responses by the T cell mitogen concanavalin A remained normal in animals receiving transfusion alone or with CyA. In contrast, profound inhibition of mitogenic responses was observed in FK506-treated animals and this inhibitory effect declined gradually following drug withdrawal. No non-specific suppressor cell activity was detected in the spleens of rats given transfusion alone or in CyA or FK506-treated transfused animals.

FK506--its influence on anti-class 1 MHC alloantibody responses to blood transfusions

The influence of FK506 on in vivo alloantibody responses to major histocompatability class 1 antigens was investigated in inbred rat strains, and compared with the effect of cyclosporine. AO rats received transfusions of DA blood on days 0 and 7. From days 0 to 14 the rats also received, daily, either FK506 0.3 mg/kg suspended in saline or dissolved in olive oil, or CsA 10 mg/kg. The administration of FK506 suspended in saline at the time of blood transfusion completely abrogated the development of anti-MHC class 1 alloantibodies as detected by indirect hemagglutination (IHA)* and 51Cr release complement dependent cytotoxicity assays (CDC). Isotyping studies showed that FK506 suspended in saline suppressed IgM production and inhibited the switch to IgG production. Similar responses were seen in CsA-treated animals. In contrast, rats treated with FK506 dissolved in olive oil developed high titers of anti-class 1 alloantibodies. On days 49 and 56 the rats were challenged with further DA blood transfusions given without immunosuppression. In the groups given FK506 suspended in saline or CsA, cytotoxic antibodies did not develop; low titer antibodies were, however, detected by IHA in the animals that had previously received FK506 suspended in saline. The results indicate that FK506, in common with CsA, inhibits anti-class 1 MHC alloantibody production, and at the same time enables the development of tolerance. The vehicle in which FK506 is administered is, however, critical to its efficacy at the low doses used. These results may be of relevance to clinical transplantation as similar antibodies mediate hyperacute renal allograft rejection in man.

Glomerulotubular function in long-term renal allograft recipients. A comparison of conventional therapy with cyclosporine

Glomerular and tubular function were assessed, using a lithium clearance technique, in two groups of renal allograft recipients at least one year after transplantation. Group 1 comprised 14 patients receiving low-dose prednisolone and cyclosporine, and group 2, 14 patients receiving low-dose prednisolone and azathioprine. There were no significant differences in creatinine clearances between the two groups, although the clearances of lithium (which is absorbed almost exclusively from the proximal tubule) and sodium were significantly lower in the cyclosporine-treated group. Fractional lithium excretion was also significantly lower in group 1 than in group 2, but there was no significant difference in fractional sodium excretion. The absolute proximal reabsorption of sodium and water did not differ between the groups, although the fractional proximal reabsorption of sodium and water was significantly higher in group 1. In contrast, the distal reabsorption of sodium and of water was significantly lower in the cyclosporine-treated patients than in the azathioprine-treated patients; there were, however, no significant differences in the distal fractional reabsorptions of sodium and water between the two groups. In addition there was no correlation in group 1 between whole-blood cyclosporine levels or time since transplantation and any of the assessed parameters of renal function. These results indicate that tubular concentrating abnormalities in cyclosporine-treated renal allograft recipients are similar to those observed in rodent models of cyclosporine nephrotoxicity. They suggest that the pathogenesis of cyclosporine nephrotoxicity may be similar in renal allograft recipients to that in experimental models.

The effect of nifedipine on graft function in renal allograft recipients treated with cyclosporin A

The effect of the calcium channel antagonist nifedipine on renal allograft function was assessed in two groups of renal transplant recipients at least one year after transplantation. Group 1 comprised 10 patients receiving low-dose prednisolone and cyclosporin A, and Group 2 comprised 9 patients receiving low-dose prednisolone and azathioprine. Before commencing nifedipine, creatinine and sodium clearance rates and the fractional excretion of sodium were similar in both two groups. Lithium clearance rates and the fractional excretion of lithium were, however, significantly lower (p less than 0.01) in Group 1 than in Group 2. The absolute reabsorption of sodium from the distal nephron (p less than 0.01), the absolute reabsorption of water from the distal nephron segment (p less than 0.01) and the fractional reabsorption of sodium from the distal tubule relative to the delivery of sodium from the proximal tubule (p less than 0.05) were also lower in Group 1. After seven days of nifedipine treatment (10 mg/8 h) there was a significant fall in sodium clearance (p less than 0.01) and fractional sodium excretion (p less than 0.05), and an increase in the fractional distal reabsorption of sodium relative to the delivery of sodium from the proximal tubule (p less than 0.01), and the fractional distal reabsorption of water relative to the delivery of water from the proximal tubule (p less than 0.02), in Group 1 but not Group 2. The only alterations observed in Group 2 were an increase in fractional lithium excretion (p less than 0.05), and a significant fall in the absolute proximal tubular reabsorption of iso-osmotic fluids (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Acute transverse myelopathy complicating systemic lupus erythematosus

A sixteen year old girl with systemic lupus erythematosus developed acute transverse myelopathy. She was treated with high dose steroids, cyclophosphamide, and plasma exchange and regained partial neurological function. Previous descriptions of transverse myelopathy complicating systemic lupus erythematosus are reviewed, with particular reference to the efficacy of high dose steroid treatment.

Abdominal pancreatic pseudocyst--an unusual cause of dysphagia

A 44 year old man with a long history of alcohol abuse developed progressive dysphagia. Radiological investigation revealed a pancreatic pseudocyst. Following percutaneous drainage the dysphagia resolved.